I had almost the same question. So let me quickly share what I came up with.
I have a ton of notes in different areas. By I was not happy with the way Obsidian worked – synchronization specifically. I didn't want to pay for it. So I got on a quest for the perfect note-taking system. It had to be:
- Markdown-first. Because we all know why;
- Interoperable. That is as few additional flavors and things added as possible;
- Portable. Such that I could open my Notes folder in any app;
- Synchronization. With as few additional crutches as possible.
Main text editor
Desktop. I use !helix@programming.dev. It has marksman LSP (meaning markdown support out of the box). This is how I know no other app is involved into writing process (no telemetry, etc). Also zero task switching this way. I still use !obsidianmd@lemmy.world from time to time. I don't use Logseq because it has opinionated file structure, which doesn't meet my interoperability need. Also, I don't always need an outliner. You can turn this feature on in Obsidian, but you can't turn it off in Logseq.
Mobile. I use the simplest markdown-capable apps for iOS and Android. Also, don't forget Cryptomator.
Sync. For the most part I use !syncthing@lemmy.ml to sync all the notes. Such that they are not uploaded into any cloud storage. I don't use iCloud, or rather almost never use it.
As for your question. Obsidian is a pretty good choice because of its extensibility, portability, and interface. Although it easy to get lost in the plugin rabbit hole. Its desktop and mobile (if you go for it) privacy policy is pretty solid. Client-first markdown app – nothing more and nothing else.
Lastly, there is this idea that one needs to sync notes via some cloud. Not true. You should consider your threat model first. Cloud sync is not must. In some cases, Syncthing is more than enough, is more private, and might be a more secure option (as it reduces your surface of attack to some extent).
I guess that's all